Vehicle having seats with head restraint is considered as one of the primary method of preventing a whiplash-induced injury in motor vehicles. A well designed and correctly aligned head restraint will vastly reduce the risk of injury to the head, spine and neck during rear-end collisions. Head restraint geometry, specifically head restraint height and horizontal distance ‘setback’ of the head restraint from the occupant's head can have a significant influence on the likelihood and severity of a whiplash injury in rear impact collisions. Most of the front seat occupants fail to adjust their head restraints correctly or have head restraints that are incapable of offering any protection. Whiplash can be prevented with a good head restraint system that is correctly positioned. To be effective, a head restraint must be as close to the back of the head as possible and the top of the restraint should be as high as the top of the head.
Generally, there are two types of the head restraint system i.e. active and passive. The active head restraint system is good at comfort since its position is ergonomically apt for an occupant and it instantaneously adjusts itself to offer safety in case of a crash. The passive head restraint systems are stationary. The passive head restraint system does not offer any swivel or angular adjustment. In a passive head restraint system the head restraint is placed very close to the head to avoid the bending of the neck during rear impact. Though it increases safety it results in lack of comfort for occupant.
Therefore, there is a need for an improved head restraint system (particularly the passive head restraint system) for providing all the advantages of the active head restraint system using passive components. Additionally, the improved head restraint system should be able to prevent whiplash injury.